JP2007023431A - Carbon fiber woven fabric and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a unidirectional carbon fiber woven fabric capable of increasing productivity (production rate) even when using a high fineness carbon fiber, and to provide a method for producing the fabric. <P>SOLUTION: The unidirectional carbon fiber woven fabric comprises carbon fiber thread as the warp and auxiliary fiber of another kind than carbon fiber thread as the weft which auxiliary fiber has ≤1/5 fineness based on that of the carbon fiber thread, wherein spaces between wefts are in a specific range and the weft forms selvages continuing at the fabric edges. Weaving is preferably performed by using a needle loom. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a unidirectional carbon fiber woven fabric and a carbon fiber woven fabric capable of increasing productivity (production rate) even when carbon fibers having a large fineness are used.

  Conventionally, synthetic fiber and glass fiber fabrics are woven using a needle loom (for example, Patent Document 1). This is because, for example, in the case of a synthetic fiber fabric, the breaking elongation of the synthetic fiber used is as high as 10% or more, so that it is difficult to fluff, the fineness is thin, for example, 1000 to 1500 denier (111 to 167 tex), and the woven density (number of warp yarns, Because weaving is dense, and the weaving fabric is a two-way fabric in which synthetic fibers are arranged in two directions. It is.

  On the other hand, carbon fiber fabrics are easily fluffed because the elongation at break of carbon fibers used is as low as about 1.5 to 2%, and the fineness is thick, for example, 333 to 3,333 tex, and the woven density is rough. In many cases, weaving is performed using a shuttle loom, a rapier loom, or the like (for example, Patent Documents 2 and 3).

  However, when a rapier loom is used, there is a restriction on the physical speed (number of rotations) in the weft insertion movement by the rapier, and the upper limit is a speed of less than 1.5 m / min. Therefore, there is a problem that productivity is low. Moreover, since the woven fabric woven by a general rapier loom is woven while cutting the weft yarn at the end portion of the fabric, the tufted ear composed of the cut weft yarn is present at the end portion of the fabric. Therefore, when the woven fabric is bonded to a concrete structure or the like with a resin to repair and reinforce, it is necessary to harden the tufted ear that does not retain any strength with the resin. Therefore, since such a tufted ear exists, there is a problem that not only the resin is wasted but also the area (work) to be bonded with the resin is increased.

  On the other hand, in the shuttle loom, weaving is performed without cutting the weft yarn, so that the tufted ear is not formed, and the weft yarn is an ear tissue continuously folded back at the end of the fabric. However, even in the shuttle loom, there is a restriction on the physical speed (number of rotations) in the weft insertion motion by the shuttle, and the speed is generally slower than that of the rapier loom. Further, since it is necessary to wind the weft by driving the shuttle itself with a small volume, the shuttle must be frequently replaced, and there is a problem that the productivity of the carbon fiber fabric is remarkably inferior.

  In order to solve the above-mentioned problem of productivity, Patent Document 4 discloses the content of manufacturing a carbon fiber fabric in a water jet room, and uses carbon fiber having a fineness of 200 tex to make warp and weft yarns. It is described that a plain-woven carbon fiber woven fabric composed of carbon fibers can be produced at a speed of 0.8 m / min. However, in such a method, in the carbon fiber having a fineness exceeding 200 tex, the carbon fiber is scattered and it is impossible to maintain a high-quality woven structure.

That is, in the conventional techniques including Patent Documents 1 to 4, a realistic carbon fiber woven fabric that can be applied even when using carbon fibers with a large fineness and that can realize high productivity and a method for manufacturing the same are found. There is no need for such technology.
Japanese Utility Model Publication No. 05-035870 JP 2002-115145 A JP-A-11-001839 Japanese Patent Application Laid-Open No. 06-341034

  Accordingly, the present invention aims to solve the above-mentioned problems in the background art, and provides a carbon fiber woven fabric production method and a carbon fiber woven fabric that can enhance productivity even when carbon fibers having a large fineness are used. The purpose is to do.

The present invention for achieving the above object is characterized by the following (1) to (18).
(1) A unidirectional carbon fiber fabric in which carbon fiber yarns are warp yarns and weft yarns of auxiliary fibers of a type different from carbon fiber yarns, and have a fineness of 1/5 or less of the carbon fiber yarns. The distance between the wefts formed by three adjacent wefts is non-uniform, and the wider distance X of the interweft distances is in the range of 1.2 to 50 times the other distance Y. A carbon fiber woven fabric characterized by having an ear tissue in which wefts are continuous at the end of the woven fabric.
(2) The carbon fiber fabric according to (1) above, wherein the fineness of the carbon fiber yarn is within a range of 750 to 6,000 tex.
(3) The carbon fiber fabric according to (1) or (2) above, wherein the coefficient of static friction between the carbon fiber yarns is in the range of 0.25 to 0.5.
(4) The carbon fiber woven fabric according to any one of (1) to (3) above, wherein the tensile elastic modulus measured along JIS-R7601 of the carbon fiber yarn is 290 GPa or more.
(5) The above (1) to (4), wherein the warp yarn density is in the range of 1 to 8 yarns / cm and the weft yarn density is in the range of 0.4 to 8 yarns / cm. The carbon fiber fabric according to any one of the above.
(6) The carbon according to any one of (1) to (5) above, wherein a distance between warp yarns formed by two adjacent warp yarns is in a range of 0.1 to 0.8 mm. Textile fabric.
(7) The carbon fiber woven fabric according to any one of the above (1) to (6), wherein a resin is bonded in a linear or dotted form.
(8) The carbon fiber woven fabric according to any one of (1) to (7) above, which is used for repair and reinforcement of a concrete structure.
(9) Manufacture of unidirectional carbon fiber woven fabric using carbon fiber yarns as warp yarns and weft yarns of auxiliary fibers different from carbon fiber yarns having a fineness of 1/5 or less of the carbon fiber yarns. A method for producing a carbon fiber fabric, the method comprising weaving using a needle loom.
(10) The method for producing a carbon fiber fabric as described in (9) above, wherein the weaving speed is 1.7 m / min or more.
(11) The method for producing a carbon fiber fabric as described in (9) or (10) above, wherein a carbon fiber yarn having a fineness in a range of 750 to 6,000 tex is used.
(12) A carbon fiber fabric according to any one of (9) to (11) above, wherein a carbon fiber yarn having a coefficient of static friction between carbon fiber yarns of 0.25 to 0.5 is used. Manufacturing method.
(13) The carbon fiber woven fabric production method according to any one of (9) to (12) above, wherein a carbon fiber yarn having a tensile modulus of elasticity measured according to JIS-R7601 of 290 GPa or more is used.
(14) The warp yarn density is 1 to 8 yarns / cm, the weft yarn density is 0.4 to 8 yarns / cm, the distance between the weft yarns formed by three adjacent weft yarns is non-uniform, and the weft yarns The carbon according to any one of (9) to (13) above, wherein the wider distance X of the inter-spaces is within a range of 1.2 to 50 times the other distance Y. A method for producing a textile fabric.
(15) The method for producing a carbon fiber woven fabric according to any one of (9) to (14) above, wherein the opening amount of the heald is within a range of 10 to 75 mm.
(16) The method for producing a carbon fiber woven fabric according to any one of (9) to (15) above, wherein the resin is bonded in a linear or dot form.
(17) The method for producing a carbon fiber fabric according to (16), wherein the resin is bonded by heating the fabric.
(18) The woven carbon fiber woven fabric is wound up once at a predetermined length L1, and the wound carbon fiber woven fabric is divided into product lengths L2 that are half or less of the predetermined length L1, and then wound up again. The manufacturing method of the carbon fiber fabric in any one of 9)-(17).

  According to the present invention, the carbon fiber yarn is used as the warp, the auxiliary fiber of a type different from the carbon fiber yarn having a fineness of 1/5 or less of the carbon fiber yarn is used as the weft yarn, and the needle loom is used. Since the unidirectional carbon fiber fabric is woven, productivity (production speed) can be remarkably increased.

  Moreover, the carbon fiber fabric of the present invention woven by the above method uses carbon fiber yarns as warp yarns, and is a kind of auxiliary different from carbon fiber yarns having a fineness of 1/5 or less of the carbon fiber yarns. It is a unidirectional carbon fiber woven fabric using weft yarns, and the weft yarn distance formed by three adjacent weft yarns is uneven, and the wider distance X among the weft yarn distances is already One of the distances Y is in the range of 1.2 to 50 times, and the weft has an ear tissue continuous at the end of the fabric, so that the fabric has excellent flexibility and warp straightness. It is possible to minimize the troubles when attaching the woven fabric to the concrete structure and the loss of the resin used.

  Hereinafter, preferred embodiments of the present invention will be described.

  In FIG. 1, the one fabric edge part of the carbon fiber fabric which is one Embodiment of this invention is shown.

  The carbon fiber fabric of the present invention is a unidirectional carbon fiber having a carbon fiber yarn as a warp, a fineness of 1/5 or less of the carbon fiber yarn, and an auxiliary fiber of a different type from the warp. In the woven fabric, as shown in FIG. 1, the distances X and Y between the weft yarns 2 a, 2 b, and 2 c composed of the auxiliary fibers 2 are not uniform. Further, the wider distance X (distance X between the weft yarns 2a and 2b) of the distance between the weft yarns is 1.2% of the other shorter distance Y (distance Y between the weft yarns 2a and 2c). ˜50 times, that is, X = 1.2Y˜50Y. More preferably, it is 1.4-25 times, More preferably, it is 2-15 times.

  The carbon fiber woven fabric of the present invention can be woven using a needle loom even when a carbon fiber yarn having a high fineness is used by producing such a specific type of yarn as warp and weft. The performance (production speed) can be significantly increased.

  In addition, the carbon fiber fabric of the present invention can have both the flexibility of the fabric and the straightness of the warp yarn by the configuration having the specific inter-weft distance. In other words, the present invention provides a weft distance between weft yarns made of carbon fiber yarns and a weft yarn of a type different from carbon fiber yarns, which has a fineness of 1/5 or less of the warp yarn fineness. The long distance X and the short distance Y having a specific relationship are repeated at a constant cycle, so that the fabric flexibility is mainly expressed by the distance X, and the straightness of the warp is expressed mainly by the distance Y. And found that the balance between the two can be achieved.

  Furthermore, the unidirectional carbon fiber fabric of the present invention has an ear tissue in which wefts are continuous at the fabric end. That is, it does not have a tufted ear formed by cutting the weft yarn at the end of the fabric. By having such an ear tissue, for example, when repairing and reinforcing a unidirectional fabric by bonding it to a concrete structure or the like with a resin, not only the loss of the resin but also the bonding area (labor) is minimized. It can be suppressed to the limit. From this point of view, it is preferably used for repair / reinforcement used in the civil engineering / architectural field.

  Here, as a carbon fiber yarn used as a warp, it is preferable that the fineness is 750-6,000 tex. More preferably, it is the range of 1,500-4,000 tex. When the fineness is less than 750 tex, the weave density of the warp yarn becomes too dense, the fluff of the carbon fiber yarn increases, and the quality of the carbon fiber fabric may be impaired. On the other hand, if it exceeds 6,000 tex, the shape stability of the carbon fiber fabric is inferior, and the gap between the warp yarns becomes too large to form a resin-rich portion when CFRP (carbon fiber reinforced plastic) is molded. As a result, the mechanical properties of CFRP tend to be lowered. From another point of view, if the fineness is in the above range, the carbon fiber yarn can be obtained at a low cost, so that the carbon fiber fabric can be made at a lower cost.

  Moreover, it is preferable that the static friction coefficient (mu) between a carbon fiber yarn and a carbon fiber yarn exists in the range of 0.25-0.5. More preferably, it is 0.3-0.45, More preferably, it is the range of 0.3-0.35. When the coefficient of static friction μ is less than 0.25, although scratching due to friction is difficult to occur, the carbon fiber yarns are inferior in converging property, and due to the lack of converging property, the yarns may be scattered and fluffed. . On the other hand, when the static friction coefficient μ exceeds 0.5, the ends of adjacent warp yarns, or warp yarns and weft yarns may be rubbed, and the carbon fiber yarn may be easily fluffed. The carbon fiber fabric of the present invention preferably has a warp density in the range of 1 to 8 yarns / cm and a weft yarn density in the range of 0.4 to 8 yarns / cm. More preferably, the warp yarn density is 2 to 6 yarns / cm, the weft yarn density is 1 to 6 yarns / cm, and still more preferably the warp yarn density is 3 to 5 yarns / cm, and the weft yarn density is 2 to 5 yarns / cm.

  When the warp yarn density is less than 1 / cm, not only the shape stability of the carbon fiber woven fabric is inferior, but also the gap between the warp yarns becomes too large, which may deteriorate the mechanical properties of CFRP (carbon fiber reinforced plastic). On the other hand, if the warp yarn density exceeds 8 yarns / cm, the fluff of the carbon fiber yarn increases, and the quality of the carbon fiber fabric may be impaired.

  Moreover, when the weft density is less than 0.4 yarn / cm, the shape stability of the carbon fiber fabric is inferior and the handleability of the fabric is likely to be inferior. On the other hand, if the weft density exceeds 8 / cm, it may be difficult to increase the production rate of the carbon fiber fabric.

  The warp density or weft density refers to a value calculated by reading 30 distances (Z) / Z (cm) of the distance Z corresponding to 30 warp threads or weft threads to the unit of 1 mm (unit: book / cm). ).

  Furthermore, in the carbon fiber fabric of the present invention, it is preferable that the distance between the warp yarns formed by two adjacent warp yarns is in the range of 0.1 to 0.8 mm. More preferably, it is 0.15-0.6 mm, More preferably, it is the range of 0.2-0.5 mm. When the distance between the warp yarns is less than 0.1 mm, the fluff of the carbon fiber yarns increases, which may impair the quality of the carbon fiber fabric, and when the CFRP is molded by impregnating the matrix resin, The impregnation of the resin may be hindered. On the other hand, if the gap exceeds 0.8 mm, when CFRP is molded, a resin-rich portion may be formed large and the mechanical properties of CFRP may be reduced.

  Furthermore, it is preferable that the carbon fiber woven fabric of the present invention is stabilized by adhering a resin in a linear or dot form. A preferable adhesion amount of the resin is in the range of 2 to 20% by weight, and a more preferable adhesion amount is in the range of 5 to 17% by weight, when the carbon fiber woven fabric to which the resin is adhered is 100% by weight. As a result, the handleability of the carbon fiber fabric can be improved, and the mechanical properties of CFRP using the carbon fiber fabric can be improved. That is, when such a resin is bonded, it plays the role of a crack stopper in CFRP obtained by laminating carbon fiber fabrics and impregnating and solidifying the matrix resin. In particular, when CFRP receives an impact, it plays a role in suppressing damage and provides excellent mechanical properties (particularly, compressive strength after application of impact) (interlayer reinforcement effect).

  In addition to the toughening effect described above, when carbon fiber woven fabrics are laminated, the bonded resin serves as a spacer, and a space is formed between layers of carbon fiber woven fabrics adjacent in the thickness direction. Such space serves as a flow path for the matrix resin when the matrix resin is injected to form the CFRP (interlayer flow path forming effect). This not only facilitates the impregnation of the matrix resin, but also increases the impregnation rate, resulting in excellent CFRP productivity.

  If the amount of the resin adhered exceeds 20% by weight, the carbon fiber blending ratio when CFRP is used becomes too low, and the mechanical properties may be inferior. In addition, when the carbon fiber fabrics are bonded together by heating, the resin is deformed, so that the flow path of the matrix resin may be crushed and the impregnation may be hindered. On the other hand, if the adhesion amount of the resin is less than 2% by weight, the above effects may not be sufficiently exhibited.

  Such a resin is preferably bonded to the surface of the carbon fiber fabric, but may be bonded to the inside of the carbon fiber fabric, that is, inside the carbon fiber yarn (between the carbon fiber filaments) other than the surface. . However, since the above-described interlayer reinforcing effect and interlayer flow path forming effect are particularly effective when the resin adheres to the surface, the resin exists only on the surface of the carbon fiber fabric. preferable. If it is present only on the surface, the amount of resin adhered can be minimized, the carbon fiber blending ratio when CFRP is used can be further increased, and the lightening effect can be further enhanced. it can.

  And when providing resin on the surface of a carbon fiber fabric, this resin may adhere to the single side | surface of the carbon fiber fabric, or may adhere to the both surfaces. The former is preferred when producing a carbon fiber fabric at a lower cost. If you do not want to use the front and back of the carbon fiber fabric properly, the latter is preferable and can be used according to the purpose.

  The type of the resin is not particularly limited as long as it improves the handleability of the carbon fiber woven fabric or improves the mechanical properties of CFRP, but a thermosetting resin or a thermoplastic resin is appropriately selected and used alone or in combination. Can be used.

  In the case of imparting the function of improving the handling of the woven fabric, it is preferably at least one selected from epoxy, unsaturated polyester, vinyl ester, polyamide, polyester and polyolefin, and among them, epoxy and polyamide are particularly preferable. Such a resin has a melting point Tm (glass transition point + 50 ° C. for those having no melting point) of 150 ° C. or less measured by DSC (differential scanning calorimeter) from an absolutely dry state at a temperature rising rate of 20 ° C./min. Preferably there is.

  In addition, when imparting the function of improving the mechanical properties of CFRP, epoxy, unsaturated polyester, vinyl ester, phenol, bismaleimide, polyamide, polysulfone, polyethersulfone, polyetherimide, polyphenylene ether, polyimide, polyamideimide At least one selected from phenoxy is preferable, and among them, epoxy, polyamide, polyetherimide, polyphenylene ether, polyethersulfone, and phenoxy are particularly preferable. In addition, the said resin may be individual, and may use multiple things together and may give them mixed or separately.

  The carbon fiber woven fabric of the present invention as described above has at least carbon fiber yarns as warp yarns, and auxiliary yarns of a different type from carbon fiber yarns having a fineness of 1/5 or less of carbon fiber yarns as weft yarns. It can be woven using a needle loom. At this time, the weaving speed is preferably 1.7 m / min or more. A more preferred weaving speed is 2 m / min, even more preferably 2.5 m / min or more. When the speed is lower than the above speed, the meaning of weaving using a needle loom becomes dilute. There is no upper limit to the weaving speed, and a faster speed is preferable. However, 15 m / min is considered to be the upper limit in the presently considered technical range.

Conventionally, shuttle looms, rapier looms, and the like have been used in the production of carbon fiber fabrics, but high productivity, that is, high production speed (rotation speed of the loom) has not been realized. This is because the weaving mechanism of the loom, the woven fabric to be woven, and the carbon fiber used have the following restrictions.
A. Restrictions on the weaving mechanism of the loom (1) When a shuttle loom or rapier loom is used, there is an upper limit on the physical speed in the weft insertion motion by the shuttle or rapier as the weft insertion means.
(2) Regarding weft insertion, when weaving at high rotation, the weft insertion means and the warp yarn are in direct contact, or the warp yarn and the support for running the shuttle or rapier are in direct contact with each other and are scraped. Carbon fiber yarns can be easily fluffed.
(3) Regarding the supply of the warp yarn, when weaving at high rotation, the ends of the adjacent warp yarns are rubbed by the opening movement of the warp yarn, and the carbon fiber yarn is easily fluffed.
B. Restriction of weaving fabric (1) In the case of a bi-directional fabric using carbon fiber yarns for warp and weft, depending on the weaving machine and weaving conditions, weft insertion means ( The carbon fiber yarn is easily fluffed by rubbing between the weft and the weft (including those guides) and rubbing by direct contact between the warp and weft.
C. Restriction of carbon fiber to be used (1) Since the breaking elongation of the carbon fiber yarn is low, it is easily fluffed.

  In the present invention, a needle loom is used to meet the restrictions of the items A (1) and (2). By using a needle loom, the influence of the weight (inertia) of weft insertion means such as a shuttle or rapier can be greatly suppressed. And since the carbon fiber fabric is woven using the needle loom, the weft can be a continuous fabric at the end of the fabric, that is, the fabric without the tufted ears. As a result, the fabric can be a concrete structure or the like. It is possible to minimize the time and trouble of pasting on the resin and the loss of the resin used.

  Further, with respect to the restriction of the above item B (1), the carbon fiber yarn is warp and the fineness is 1/5 or less of the carbon fiber yarn which is the warp and is different from the carbon fiber yarn. Weaving unidirectional fabrics using a kind of auxiliary fiber in the weft. When the fineness ratio exceeds 1/5, it means that the auxiliary fiber is too thick, and there is a case where the mechanical properties are lowered by bending the carbon fiber yarn in the unidirectional fabric. The fineness ratio is more preferably in the range of 1/20 to 1/500, and still more preferably in the range of 1/100 to 1/250. If it is less than 1/500, it means that the strength of the auxiliary fiber becomes too low, and there are cases where many weft breaks occur during weaving.

  Auxiliary fibers include inorganic fibers other than carbon fibers such as glass fibers, metal fibers, ceramic fibers, aramid fibers, PBO fibers, polyamide fibers, polyester fibers, polyvinyl alcohol fibers, polyethylene fibers, polypropylene fibers, polyphenylene sulfide fibers, etc. Among them, inorganic fibers other than carbon fibers, which have a small shrinkage ratio during heating and can minimize shrinkage in the width direction of the carbon fiber fabric, are preferable, and glass fibers are particularly preferable. Further, from the viewpoint of reducing the fineness and suppressing the bending of the carbon fibers, organic fibers having a fineness, particularly polyamide fibers, are preferable.

  When weft insertion is performed with a needle loom using carbon fiber yarns for temporary weft yarns, there is a problem that the carbon fiber yarns fluff easily, and the generated fluff clogs the needle guide etc. As described above, since the auxiliary fiber of a different type from the carbon fiber yarn is used for the weft yarn, the above problem does not occur even when the needle loom is used, and the productivity of the carbon fiber fabric can be improved.

In the present invention, the carbon fiber yarn that is the warp has a static friction coefficient μ between the carbon fiber yarn and the carbon fiber yarn of 0.25 to 0.00. 5 is preferable. More preferably, it is 0.3-0.45, More preferably, it is the range of 0.3-0.35. When the coefficient of static friction μ is less than 0.25, although scratching due to friction is difficult to occur, the carbon fiber yarns are inferior in converging property, and due to the lack of converging property, the yarns may be scattered and fluffed. . On the other hand, if the static friction coefficient μ exceeds 0.5, the ends of adjacent warps, or warps and wefts, are abraded as described in item A (3) and item B (1), and the carbon fiber yarn May be easily fluffed.
In addition, this static friction coefficient (micro | micron | mu) points out the value measured according to the following procedure.

In FIG. 2, the schematic perspective view of the measuring apparatus 20 of the static friction coefficient (mu) between the carbon fiber yarns of this invention is shown.
(A) A bobbin 6 around which the carbon fiber yarn 1 is wound is prepared, the carbon fiber yarn is pulled out from the bobbin 6 and cut, and both ends of the carbon fiber yarn 1 are connected to form a ring having a diameter of about 3 cm. . In addition, when the carbon fiber yarn 1 on the surface of the bobbin 6 of the carbon fiber yarn 1 is damaged, i.e., fluffy, at least 10 m or more of carbon fibers so that the bobbin surface state of the original carbon fiber yarn is obtained. Discard yarn 1 and sample.
(B) Next, the carbon fiber yarn 1 is fixed to the end portion of the paper tube 7 with a tape so that the end portion of the yarn is not unwound, and the bobbin holder 3 is set with a horizontal axis. Set the bobbin 6 in Here, the bobbin holder 3 to be used is one that rotates with a force of 5% or less of the tension measured by a push-pull gauge described later.
(C) Thereafter, as shown in FIG. 2, the carbon fiber yarn 1 cut to about 1 m is wound around the bobbin 6 by 1.5 turns. Here, when winding, the carbon fiber yarn 1 is prevented from entering false twist.
(D) A 150 g weight 4 is attached to one end (ring) of the wound carbon fiber yarn 1, and a push-pull gauge 5 is attached to the other end.
(E) Pull the push-pull gauge 5 vertically downward and read the scale of the push-pull gauge 5 when the weight 4 starts moving.
(F) Using the measured value, the static friction coefficient μ is calculated by the following equation (A).

Static friction coefficient μ = ln (T1 / T2) / θ Formula (A)
T1: Tension measured with push-pull gauge (gf)
T2: Weight of weight (gf) = 150 g
θ: contact angle (rad) = 3π
(G) Thereafter, while maintaining the adhesive fixing position with the tape, the portion where the carbon fiber yarn 1 is wound in (c) is shifted, and (c) to (f) are repeated twice, and the n number is set to 6. The average value thereof is taken as the static friction coefficient μ of the measurement sample.

  Furthermore, in the present invention, it is preferable that the opening amount of the heddle is 10 to 75 mm with respect to the restriction of the item A (3). More preferably, it is 30-70 mm, More preferably, it is the range of 35-65 mm. When the opening amount of the heald is within such a range, at the time of weaving at high rotation, it is possible to minimize rubbing between adjacent warp yarn ends and to suppress fluffing of carbon fiber yarns. More specifically, if the opening amount exceeds 70 mm, the carbon fiber yarns may become fuzzy. On the other hand, if the opening amount is less than 10 mm, the formation of the shed (space for passing the needle) is not sufficient, and not only the weft thread can be inserted stably, but also the friction between the warp and the weft thread is relatively strong. And fluff may occur.

  Moreover, in this invention, it is preferable to use the carbon fiber yarn whose tensile strength measured along JIS-R7601 is 4,000 Mpa or more with respect to the restrictions of the said C term (1). More preferably, it is 5,000 MPa or more. When the tensile strength is in such a range, fluff is unlikely to occur and a high-quality carbon fiber fabric can be produced. In addition, although there is no upper limit in tensile strength and the higher one is preferable, 7,000 MPa is considered to be an upper limit in the presently considered technical range.

  According to the production method of the present invention, fuzz can be suppressed even when a carbon fiber yarn having a tensile modulus of elasticity of 290 GPa or more measured according to JIS-R7601 is used, and the effect of the present invention is maximized. It is preferable because it can be expressed. More preferably, it is 380 GPa or more. In addition, although there is no upper limit in tensile elasticity modulus and the higher one is preferable, 700 GPa is considered to be an upper limit in the technical range currently considered.

  In the method for producing a carbon fiber fabric of the present invention, it is preferable to use a carbon fiber yarn having a fineness of 750 to 6,000 tex. More preferably, it is the range of 1,500-4,000 tex. When the fineness is less than 750 tex, the weave density of the warp yarn becomes too dense, and as described in the above item A (3), the fluff of the carbon fiber yarns may increase and the quality of the carbon fiber fabric may be impaired. On the other hand, if it exceeds 6,000 tex, not only the shape stability of the carbon fiber fabric is inferior, but also the warp yarn gap becomes too large, and when CFRP is molded, a resin-rich portion is formed larger and the mechanical properties of CFRP are reduced. There is a case to let you. From another point of view, when the fineness is in the above range, the carbon fiber yarn can be obtained at low cost, and the carbon fiber fabric according to the present invention can be produced at a lower cost.

  Furthermore, in the method for producing a carbon fiber fabric of the present invention, it is preferable that a resin is bonded to the fabric to be produced in a linear or dot form. When the resin is bonded to the woven fabric, the form of the carbon fiber woven fabric can be stabilized, and a function of improving the handleability of the carbon fiber woven fabric can be imparted. From another viewpoint, it is also possible to provide a function of improving the mechanical properties of CFRP using a carbon fiber fabric.

  In order to bond the resin in such a form, the resin may be applied to the carbon fiber fabric in any form such as a fiber form, a particle form, an emulsion form or a dispersion form dissolved or dispersed in water. Among these, from the viewpoint of easy adhesion and the above-described expression of the functions, it is preferable to apply the adhesive to the woven fabric in the form of solid fibers or solid particles.

  In the case of such a fiber form, carbon fiber yarns and auxiliary fibers may be aligned, or carbon fiber yarns and auxiliary fibers formed with composite yarns by covering processing, twisting processing or blending may be used. In particular, when adding a function to improve the handling of the fabric, weave the fiber-shaped resin as a weft thread, or insert it into a composite thread by covering or twisting with carbon fiber or auxiliary fiber. When inserted as a function, it is possible to effectively provide a function.

  On the other hand, in the case of particle form, emulsion form, or dispersion form, a carbon fiber or auxiliary fiber that has been previously applied and adhered may be woven, or may be applied after being woven, and may be quantitatively added. In the case of imparting to a carbon fiber fabric, the latter is more preferable because it is more reliable.

  In addition, as a resin to be used, the above-mentioned types can be used.

  As a method of adhering such a resin, the carbon fiber woven fabric and the heat source may be brought into contact with each other and heated, or the carbon fiber woven fabric and the heat source are not brought into contact with each other, and the attached resin is adhered by heating in a non-contact manner. May be. In the present invention, since weaving is performed at an extremely high speed, it is preferable to heat the carbon fiber fabric and the heat source in contact with each other. More preferably, the method of heating by contacting with a heat source and the method of heating without contacting may be used in combination. In the present invention, since carbon fibers having excellent heat conductivity are used, the resin can be efficiently bonded even at a high speed by arranging a plurality of the heat sources in the production process of the carbon fiber fabric. .

  Examples of such a heat source include a heating roll and a hot plate in the contact type. In the non-contact type, a radiant heater such as a far infrared ray or a near infrared ray can be used.

  In the present invention, in order to further increase the productivity, it is preferable to use a needle loom capable of simultaneously weaving three or more fabrics with one unit. On the other hand, when weaving many woven fabrics at the same time, if there is an insertion error or entanglement error in one woven fabric, the weaving machine itself stops and weaving of all the woven fabrics is interrupted, which may impair productivity. Therefore, it is not preferable to simultaneously weave 10 or more fabrics with one unit.

  Furthermore, in order to further increase the productivity, the woven carbon fiber woven fabric is wound up once with a predetermined length L1, and the wound carbon fiber woven fabric is divided into product length L2 that is half or less of the predetermined length L1, and then wound up again. It is preferable. Since the carbon fiber fabric of the present invention is mainly used as a reinforcing material for CFRP, if it is packed without being wound up like a synthetic fiber fabric produced by a needle loom, the carbon fiber yarn will be wrinkled and bent. There is a case where the strip is damaged or the arrangement (straightness) of the carbon fiber yarn is disturbed. For this reason, the wound form is preferably a product form. On the other hand, on the premise of winding, even if a high production speed is achieved by the present invention, if the product length L2 is short, it is necessary to frequently stop the loom, and the effect of the present invention is efficiently exhibited. It is hard to be done. Therefore, as described above, the loom is stopped by continuously weaving a predetermined length L1 that is two times longer than the product length L2 and winding it around an intermediate core (for example, a paper tube, an iron tube, etc.) different from the product core. The frequency can be minimized and a higher production speed (the speed of the loom) can be achieved. It is preferable that the carbon fiber woven fabric of the predetermined length L1 once wound up is divided into product lengths L2 that are half or less of the predetermined length L1 in a separate process and wound up again. A more preferable predetermined length L1 is at least three times the product length L2. From another point of view, the preferable predetermined length L1 is 100 m or more. More preferably, it is 200 m or more, More preferably, it is 300 m or more.

Example 1
A carbon fiber yarn having a fineness of 800 tex (tensile strength measured according to JIS-R7601 = 4,900 MPa, tensile elastic modulus = 235 GPa, static friction coefficient 0.34, twist number 0 turns / m) is used for the warp yarn. A warp yarn density using a weft yarn obtained by covering a glass fiber (ECE225 1/0 1.0Z) with a copolymer nylon yarn (5.5 tex, melting point 110 ° C.) at 300 turns / m (fineness 28 tex). A unidirectional woven fabric (carbon fiber basis weight 200 g / m ² ) having a weft density of 2.5 / cm and a weft density of 3 / cm was woven by a needle loom. Weaving was performed at a speed of 1.8 m / min and a heald opening amount of 65 mm. The weaving width was 15 cm and three rows of fabrics were woven together.

  After weaving, the resulting woven fabric is heated while being in direct contact with the three heating rollers that are the heat source and without being in contact with the three infrared heaters that are the other heat sources, and the copolymer nylon used for the weft The yarn was bonded to a carbon fiber yarn and three rows of fabric were wound together around a 80 mm outer diameter paper tube.

  In such weaving, the occurrence of fluff at warp healds and wrinkles was suppressed, and continuous weaving of 300 m was possible. The 210 m long woven fabric once wound up was divided into four 50 m long rolls using a separately prepared rewind device (inspection device) and rolled back into a paper tube with an outer diameter of 80 mm to obtain a product.

The obtained unidirectional woven fabric was abraded with linearly bonded copolymer nylon yarns, and was excellent in handleability. Further, the distance between the wefts formed by three adjacent wefts was uneven, and the wider distance X of the interweft distances was 10 times the other distance Y. Such weft is an ear tissue that is continuous at the end of the fabric, and is simply folded back at one end and forms a warp knitted structure at the other end, and does not have a tufted ear. It was. Furthermore, since the gap between the warp yarns was 0.2 mm and the gap was sufficiently wide, the impregnation property when impregnated with the resin was excellent.
(Example 2)
Carbon fiber yarn with a fineness of 445 tex on the warp (tensile strength measured in accordance with JIS-R7601 = 3,800 MPa, tensile modulus = 438 GPa, static friction coefficient 0.4, twist number 0.2 turns / m) Are used, and the weft yarn is covered with glass fiber (ECE225 1/0 1.0Z) and copolymer nylon yarn (5.5 tex, melting point 110 ° C.) at 300 turns / m (fineness 28 tex). ), A unidirectional woven fabric (carbon) with a warp density of 6.7 yarns / cm (3.3 yarns / cm when treated as a single piece of two drawn yarns) and a weft yarn density of 6 yarns / cm. A fiber basis weight of 300 g / m @ 2) was woven using a needle loom. Weaving was performed at a speed of 1.8 m / min and a heald opening amount of 65 mm. The weaving width was 15 cm and three rows of fabrics were woven together.

  After weaving, the resulting woven fabric was heated in the same manner as in Example 1, the copolymer nylon yarn was bonded to the carbon fiber yarn, and three rows of woven fabric were wound together around a paper tube having an outer diameter of 80 mm.

  In such weaving, the occurrence of fluff at warp healds and wrinkles was suppressed, and continuous weaving of 300 m was possible. The 210 m long woven fabric once wound up was divided into four 50 m long rolls in the same manner as in Example 1 and rolled back to obtain a product.

The obtained unidirectional woven fabric was abraded with linearly bonded copolymer nylon yarns, and was excellent in handleability. Further, the distance between the wefts formed by three adjacent wefts was uneven, and the wider distance X of the interweft distances was three times the other distance Y. Such a weft yarn is an ear tissue continuous at the end of the fabric, a knitting yarn that is simply folded at one end and forms a warp knitting structure at the other end (separate from the weft yarn). At the same time, a knitted tissue was formed, and it did not have a tufted ear. Furthermore, the gap between the warp yarns was 0.12 mm.
(Comparative Example 1)
Carbon fiber yarn with a fineness of 200 tex for warp and weft (Torayca T300B-3K manufactured by Toray, tensile strength measured in accordance with JIS-R7601 = 3,540 MPa, static friction coefficient 0.18, twist number 0.1 turn / M) was used to weave a bi-directional woven fabric (carbon fiber basis weight 200 g / m @ 2) having a warp density and a weft density of 5 / cm with a water jet loom. Weaving was performed at a speed of 0.8 m / min and a heald opening amount of 80 mm.

  After weaving, the resulting woven fabric was directly brought into contact with four rollers as heat sources to dry the moisture adhering to the carbon fiber yarn.

  In such weaving, a large amount of fluff was generated in the weft threaded portion, warp heald, and wrinkle, and continuous weaving of 200 m or more was difficult without removing the fluff after stopping.

  The obtained bidirectional fabric had a uniform weft distance formed by three adjacent wefts. Such wefts were cut off at the ends of the fabric to form discontinuous ear tissues, and had a 7 mm long tufted ear. Such a tufted ear not only leads to troubles when sticking to a concrete structure and a loss of affixing resin to be used, but also increases the loss of weft yarn.

  As described above, according to the method for producing a carbon fiber fabric of the present invention, productivity can be increased even when carbon fibers having high fineness are used, and the obtained carbon fiber fabric is flexible and warp. It is excellent in straightness, and it is possible to minimize the troubles when attaching the woven fabric to the concrete structure and the loss of the resin used. For this reason, such a carbon fiber woven fabric is suitable as a reinforcing material for repair and reinforcement used in the general industrial field, particularly in the civil engineering / architectural field, and a CFRP reinforcing material used in the aircraft field.

It is a schematic plan view which shows one fabric edge part of the carbon fiber fabric of this invention. It is a schematic perspective view which shows the measuring apparatus of the static friction coefficient (micro | micron | mu) between carbon fiber yarns.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon fiber yarn 2 Auxiliary fiber 2a, 2b, 2c Weft 3 Bobbin holder 4 Weight 5 Push pull gauge 6 Bobbin 7 Paper tube X Wide inter-weft distance Y Narrow inter-weft distance 10 Carbon fiber fabric 20 Static coefficient of friction μ Measuring equipment

Claims (18)

  A unidirectional carbon fiber woven fabric using a carbon fiber yarn as a warp, and having a fineness of 1/5 or less of the carbon fiber yarn, and a weft yarn of a different type of auxiliary fiber from the carbon fiber yarn, The distance between the wefts formed by the three wefts that match is non-uniform, and the wider distance X of the interweft distances is in the range of 1.2 to 50 times the other distance Y, A carbon fiber woven fabric characterized by having an ear tissue in which the weft is continuous at the end of the woven fabric.   The carbon fiber fabric according to claim 1, wherein the fineness of the carbon fiber yarn is within a range of 750 to 6,000 tex.   The carbon fiber fabric according to claim 1 or 2, wherein a coefficient of static friction between the carbon fiber yarns is within a range of 0.25 to 0.5.   The carbon fiber fabric according to any one of claims 1 to 3, wherein a tensile elastic modulus measured according to JIS-R7601 of the carbon fiber yarn is 290 GPa or more.   Carbon according to any one of claims 1 to 4, characterized in that the warp density is in the range of 1 to 8 strands / cm and the weft density is in the range of 0.4 to 8 strands / cm. Textile fabric.   The carbon fiber woven fabric according to any one of claims 1 to 5, wherein a distance between the warp yarns formed by two adjacent warp yarns is in a range of 0.1 to 0.8 mm.   The carbon fiber woven fabric according to any one of claims 1 to 6, wherein a resin is bonded in a linear or dotted form.   The carbon fiber fabric according to any one of claims 1 to 7, wherein the carbon fiber fabric is used for repair and reinforcement of a concrete structure.   A method for producing a unidirectional carbon fiber fabric using carbon fiber yarns as warp yarns, and weft yarns of auxiliary fibers different from carbon fiber yarns, having a fineness of 1/5 or less of the carbon fiber yarns. Then, a method for producing a carbon fiber woven fabric comprising weaving using a needle loom.   The method for producing a carbon fiber fabric according to claim 9, wherein the weaving speed is 1.7 m / min or more.   The method for producing a carbon fiber fabric according to claim 9 or 10, wherein a carbon fiber yarn having a fineness in a range of 750 to 6,000 tex is used.   The method for producing a carbon fiber fabric according to any one of claims 9 to 11, wherein a carbon fiber yarn having a coefficient of static friction between carbon fiber yarns of 0.25 to 0.5 is used.   The method for producing a carbon fiber woven fabric according to any one of claims 9 to 11, wherein a carbon fiber yarn having a tensile modulus of elasticity measured in accordance with JIS-R7601 of 290 GPa or more is used.   The warp yarn density is 1 to 8 yarns / cm, the weft yarn density is 0.4 to 8 yarns / cm, the distance between the weft yarns formed by three adjacent weft yarns is non-uniform, and the distance between the weft yarns 14. The method for producing a carbon fiber woven fabric according to any one of claims 9 to 13, wherein the wider distance X is within a range of 1.2 to 50 times the other distance Y.   The method for producing a carbon fiber woven fabric according to any one of claims 9 to 14, wherein the opening of the hold is in the range of 10 to 75 mm.   The method for producing a carbon fiber woven fabric according to any one of claims 9 to 15, wherein the resin is bonded in a linear or dotted form.   The method for producing a carbon fiber woven fabric according to claim 16, wherein the resin is adhered by heating the woven fabric.   The woven carbon fiber woven fabric is temporarily wound up at a predetermined length L1, and the wound carbon fiber woven fabric is divided into product lengths L2 that are equal to or less than half of the predetermined length L1, and then wound up again. The manufacturing method of the carbon fiber fabric in any one of.

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